Dysphagia is a medical condition that effects millions of people in the United States and internationally. Patients who have dysphagia have difficulty swallowing and may also experience pain while swallowing. In particular, many patients with dysphagia have trouble swallowing liquids, foods, or saliva. Thus, eating and drinking can be a challenge for a patient with dysphagia, making it difficult for the patient to take in enough calories and fluids to nourish the body.
One common method for treating and managing dysphagia is the use of thickening agents (e.g., starch powders, modified starch powders, native xanthan gum, and guar gums) to prepare thickened beverages. Existing thickening agents, however, often have poor dispersibility, are ineffective for thickening many types of solutions at desired use levels, and fail to produce a thickened beverage that has both the required consistency and a desirable mouthfeel and taste.
For example, one frequently used thickening agent is modified corn starch. Modified corn starches, however, produce cloudy beverages and require use at high levels to sufficiently increase the beverage viscosity to the desired levels. When used as these high levels, however, the resulting beverages are pasty and have an undesirable mouthfeel. In addition, the modified corn starches also are typically shear-thickening, making them more difficult for a dysphagia patient to swallow.
Another commonly used thickening agent is native xanthan gums. Xanthan gum is a microbial polysaccharide produced by a pure culture of aerobic submerged fermentation of Xanthomonas campestris. Native xanthan gum is comprised of a 1,4 linked D-glucose backbone with trisaccharide side chains on alternating anhydroglucose units. The side chains are comprised of a glucuronic acid residue between two mannose units. Approximately 50% of the terminal mannose molecules carry a pyruvic acid residue. When xanthan gum is hydrated in an aqueous solution at typical gum concentrations (0.1 to 1 wt %) for commercial applications, a viscous but free-flowing solution is obtained. Although the native xanthan gums provide improvements over conventional starch-based thickening agents, there remain other problems with the resulting beverage.
In particular, Applicants have discovered that it is particularly desirable for a thickening agent to be capable of imparting “gel-like” properties to a composition. Gel-like properties are particularly desirable in thickening of drinkable beverages (water, tea, milk, juice, etc.) for dysphagia patients. The “gel-like” properties enable dysphagia patients to safely consume these compositions, allowing for adequate flow in the esophagus while maintaining sufficient cohesiveness that avoids aspiration into the trachea. Prior art thickening agents, however, are ineffective at producing beverages having “gel-like” properties. The use of common gelling agents, such as gellan gum, carrageenan, pectin, gelatin, etc., requires extensive preparation to form gels (e.g., heating and cooling the solutions in the presence of gelling ions). Additionally, gels that are formed using common gelling agents generally are too rigid and do not provide the desired free-flowing solution.
Accordingly, there exists a need for an effective thickening agent capable of imparting both viscous, free-flowing properties and gel-like properties to a composition while also providing a desirable mouthfeel and clarity.